List of problems
La siguiente lista de problemas se realiza en el sitio web oficial de IPT. Escriba su nombre junto con el título del problema que le permite explorar las siguientes dos semanas, después de lo que hará una presentación de 7 minutos al grupo con diapositivas en inglés. 1. High-speed CD = Daniela Ávila Durán �� = If one spins a compact disk very fast, its surface starts to warp (see video). However one can observe that the warp rotates with a different speed than the point on the surface, How do these two rotational velocities relate to each other? Be extremely careful when performing experiments! 1. CD de alta velocidad 2. Balancing pebble Stones which are taken by wind on the ice of Baikal Lake can be found after some time staying on a thin «stand». Reproduce and explain this «stand» phenomenon and estimate the curve of the stand depending on the important parameters. 3. Ink tree Edwin Leonardo Pérez Ochoa When a drop of ink is injected inside especially still water, or dropped very close to its surface, it firstly forms a ring of ink which then divides into smaller rings (see video). The process repeats again and again and forms a tree-like structure of ink. What is the maximal number of ring divisions that one can see and how does it depend on the important parameters? 4.Sound thermometer William David Suárez Cante Diseñe un método para obtener la temperatura de un fluido escuchando el sonido emitido cuando se vierte en una taza (ver video). Indique la precisión, la precisión y los límites de su método, así como los parámetros importantes del fluido. 5. Static speaker Nicolas Castillo Ojeda Build an audio speaker without any moving part. Discuss the maximum bandwidth, signal-to-noise ratio and power efficiency achieved with your design. Is it possible to modify your device to use it as a microphone? 6. Origami launcher Esteban Folded paper structures such as the Miura-ori origami can be programmed to exhibit a wide range of elastic properties depending on their crease and defect patterns. Design and build an origami cannon to vertically launch a standard Ping-Pong ball using only a single uncut sheet of A4 paper (80g/m²). How is the height of the ball elevation related to the folding pattern? Optimize your design to achieve the maximum height possible. 7. Handy glider Juan sebez jerez rodriguez It is possible to make small gliders with paper and to make them fly for a very long time by putting your hand below the glider during flight. Explain the physics behind this phenomenon and describe the optimal set of parameters for the best control of the glider. 8. LEGO Tower ''LUIS URZOLA ROJAS A LEGO mold, water and gelatin can be used to produce jelly, or ‘gummy’ LEGO bricks. It is possible to build towers using these gummy LEGO bricks in the same way as can be achieved with their plastic counterparts. What is the maximum height of gummy LEGO tower that can be built and how does this depend on the concentration of gelatin in the bricks? 9. Popcorn Andrés Felipe Rodríguez At a certain temperature, popcorn bursts open, jumps and emits a ‘pop’ sound. Devise a method to estimate the jump height of the corn kernels based on measurements of the sound of the pop and determine the limits of the precision in your chosen method. Typical parameters for consideration may include the type of corn, initial positioning of corn, heating mechanism, heat, heating rate, kernel coupling, etc. 10. Water trail A spray of water drops can be generated behind the wheels of a moving car on a wet road. How does the height and length of the spray trail that is formed depend on the speed of the car? What is the mean size of the drops that are formed? Can the drops form a mist that is thick enough to seriously reduce the visibility on a busy highway? 11. Walking chain Liliana carolina guayazan merchán If you apply a short impulse to a long chain spinning around a horizontal axis, the chain may “walk” on a short distance. Explain this phenomenon and investigate the key parameters of the distance walked. 12. Popsicle stick cobra What and how do the speed and height of the wave travelling in a popsicle stick bomb depend on? 13. The “silencer” Gloria María Peña Idrobo A nadie le gustan los vecinos que aman escuchar música a todo volumen. Proponga un diseño para un cañón electromagnético que sea fácil de hacer en casa y que genere perturbaciones electromagnéticas lo suficientemente fuertes como para interrumpir el sistema de sonido de un vecino. Proponga su propio criterio para el nivel mínimo de ruido requerido, asumiendo que su objetivo principal es hacer que su vecino deje de escuchar la música. Explica cómo cambiará la respuesta para una PC con un sistema acústico. Debe suponer que el sistema de sonido está a 5 metros de usted en una habitación vecina y que hay una pared de ferroconcreto de 0,5 m que separa las dos habitaciones. Tenga en cuenta que su instalación no debe poder lesionar al vecino o su familia y las mascotas. 14. Greenhouse effect Juan José Segura Flórez Greenhouses are used to encourage vegetable growth and to increase the temperature using nothing but solar energy. What is the highest temperature that can be reached in a 1m² greenhouse? 15. Half-empty bottle JHON WILLIAM RUBIANO BERNAL If you push a horizontally lying bottle half-full of water, it will roll forward with an oscillating speed. What does the magnitude of the oscillations in speed depend upon and how? 16. Electric fountain laura zipa Make a fountain that pumps water continuously using only the energy of two AA batteries. Determine the maximum height that the water pumped by your fountain can reach and compare this to the theoretical maximum height. Determine the key parameters that influence the maximum height. 16. Magnetic cannon DEIVID VILLAMIL Consider a line of steel balls that are stuck to a strong magnet. If an additional ball collides with the line, the final ball will be ejected at high speed. Determine the maximum speed that the final ball can have. How does this speed depend upon the position of the magnet in the line and other properties of the system? 17. Ping-Pong-Panda ''Julian Santiago Vargas R. Sometimes Ping-Pong players “chop” the ball in such a way that it changes direction after hitting the table. Estimate the maximum angle of deviation from the ball’s initial direction (i.e. a plane formed by the normal vector of the table and the velocity of the ball before bouncing) and determine what parameters it depends on. How will the answer change for a super ball? 18. Batalla de cerveza. maria camila vega Si usted tiene una botella de cerveza con el fondo de otra, la cerveza se derramará como un géiser. Explique este fenómeno y calcule la cantidad de líquido que se puede eliminar de la botella a través de este método. ¿Cuáles son los parámetros importantes para que se produzca este efecto? 19. Earth charge Measure the electric charge of the Earth. Explain your experimental procedure in detail, prove its correctness and estimate its error. Ideal solution - measure the charge using several different approaches, calculate it and show that results coincide. Does your measured charge depend on time? If yes - how? 20 Air Pocket A stable volume of air can appear near the tap end. That volume increases with time until some moment. After this moment it abruptly decreases. This situation repeats periodically. Explain the phenomenon and find the conditions for it to occur. Find out how the speed of pocket growth and period of oscillations depend on jet parameters 21. Irreversibility There is a famous experiment where aviscous liquid is placed between the walls of two coaxial cylinders. A drop of inkt hati sd ropped into the viscous liquid canv isually be spread aparta ndg atheredb acki n a drop. Is it possible to carry out this experiment usingw ater between the two cylinders instead and what parameters of the setup should be used? 22. Dry Ball DANIEL MAURICIO GUERRERO OSPINA A ping-pong ball placed over a hair dryer can float in the air, even when the air stream is inclined. What is the biggest angle for which the ball can be in equilibrium? 23. Fix an eccentric vibrator on the top of large cleaning brush. When put on a table with bristles down, the brush will start moving ahead. Study and explain this effect. Research in what way this construction can be optimized for obtaining the maximum possible efficiency. 24. Free energy from under high-voltage transmission line Stiven Guzman A fluorescent(mercury-vapor) lamp is placed under a high-voltage power line. The lamp shines. Explain this phenomenon qualitatively and describe it quantitatively. Estimate light power emitted by the lamp depending on the lamp’s parameters, the power line’s characteristics and their relative position.